Name Common Colors Streak Mohs Hardness A student has an unidentified mineral sample. The mineral is gray and leaves a white streak. The student could scratch the mineral with a copper coin that has a hardness of 3.5, but not with a fingernail that has a hardness of 2.5. Name Common Colors Streak Mohs Hardness Graphite Silver, gray, black Gray 2 Talc White, yellow, gray, green White 1 Orthoclase White, pink 6 Calcite Clear, white, gray, brown, yellow, orange, pink, blue, green 3 Based on the information in the table, which mineral does the student have? A. Graphite C. Orthoclase B. Talc D. Calcite

Which of these were the students most likely observing? Students were observing a green, odorless mineral, with no visible crystals. The mineral was very soft, with a slick feel. They compared its characteristics to the table below. Mineral Most Common Colors Hardness Other Common Characteristics Talc Gray, green, white, silver 1 Soapy feel Sulfur Yellow, yellow-brown 1.5 Greasy feel, mild rotten egg smell Halite Colorless, white, pink, yellow 2 Salty taste Quartz All colors 7 Six-sided prism-shaded crystal Which of these were the students most likely observing? A. Talc C. Halite B. Sulfur D. Quartz

3. Which of the following substances is a mineral? A. coal, which is formed with the remains of living things B. fluorite, which is a crystalline solid with the chemical formula CaF2 C. obsidian, which is a volcanic glass and is not crystalline D. brass, which is a metal that is made by humans

4. Which of the following describes a mineral’s streak? A. Resistance to being scratched Mineral’s color in powder form Reflection of light Mineral breaks in random pieces

5. Which of the following properties of minerals does Mohs scale measure? A. luster B. hardness C. density D. streak